README.rdoc

Action Pack – From request to response

Action Pack is a framework for handling and responding to web requests. It
provides mechanisms for routing (mapping request URLs to
actions), defining controllers that implement actions, and
generating responses by rendering views, which are
templates of various formats. In short, Action Pack provides the view and
controller layers in the MVC paradigm.

It consists of several modules:

Action Dispatch, which parses information about the web request, handles
routing as defined by the user, and does advanced processing related to
HTTP such as MIME-type negotiation, decoding parameters in POST, PATCH, or
PUT bodies, handling HTTP caching logic, cookies and sessions.

Action Controller, which provides a base controller class that can be
subclassed to implement filters and actions to handle requests. The result
of an action is typically content generated from views.

With the Ruby on Rails framework, users only directly interface with the
Action Controller module. Necessary Action Dispatch functionality is
activated by default and Action View rendering is implicitly triggered by
Action Controller. However, these modules are designed to function on their
own and can be used outside of Rails.